Multi-Dose Intravenous Administration of Neutral and Cationic Liposomes in Mice: An Extensive Toxicity Study

Abstract

Liposomes are widely used as delivery systems for therapeutic purposes. However, the toxicity associated with the multi-dose administration of these nanoparticles is not fully elucidated. Here, we evaluated the toxicity of the prolonged administration of liposomes composed of neutral or cationic phospholipids often used in drug and gene delivery. For that purpose, adult wild-type mice (C57Bl6) were randomly distributed into three groups receiving either vehicle (PBS), neutral, or cationic liposomes and subjected to repeated intravenous injections for a total of 10 doses administered over 3 weeks. Several parameters, including mortality, body weight, and glucose levels, were monitored throughout the trial. While these variables did not change in the group treated with neutral liposomes, the group treated with the positively charged liposomes displayed a mortality rate of 45% after 10 doses of administration. Additional urinalysis, blood tests, and behavioral assays to evaluate impairments of motor functions or lesions in major organs were also performed. The cationic group showed less forelimb peak force than the control group, alterations at the hematological level, and inflammatory components, unlike the neutral group. Overall, the results demonstrate that cationic liposomes are toxic for multi-dose administration, while the neutral liposomes did not induce changes associated with toxicity. Therefore, our results support the use of the well-known neutral liposomes as safe drug shuttles, even when repetitive administrations are needed.

Transferrin-Functionalized Liposomes for the Delivery of Gallic Acid: A Therapeutic Approach for Alzheimer’s Disease

“…Therefore, unloaded and GA-loaded liposomes were produced using distinct techniques, including lipid film hydration, reverse-phase evaporation, ethanol injection, and ethanol permeabilization, to obtain a formulation with the best physicochemical properties for brain delivery purposes. The liposomes’ composition included DSPC, CHOL, 18:0 PEG2000 PE, and DSPE-PEG2000 amine at a molar ratio of 52:45:3:0.06, which was maintained regardless of the technique since these particular NPs proved to be safe after intravenously administering 10 doses over 3 weeks to adult wild-type mice [ 26 ]. Including PEG in the liposomes composition (stealth liposomes) allows them to become invisible to the MPS, thus increasing the blood-circulation time of the lipid vesicles [ 9 ].…”

Sialic Acid Conjugate-Modified Cationic Liposomal Paclitaxel for Targeted Therapy of Lung Metastasis in Breast Cancer: What a Difference the Cation Content Makes

“…Dose-dependent toxicity may impede the practical application of cationic liposomes . Numerous animal studies have documented the toxicity associated with the administration of either a few doses or multiple doses of cationic liposomes, as well as their long-term systemic toxicity. , This toxicity can be attributed to the significant positive charge on the carriers’ surface, which electrostatically binds to the negative charge of cell membranes. Moreover, higher dosages of cationic lipids can result in elevated Zeta potentials and subsequently greater cytotoxicity, compromising their efficacy, patient quality of life, and treatment continuity .…”

“…19 Andrade et al reported that repeated intravenous administration of cationic liposomes in rodents resulted in a 45% lethality rate compared to neutral liposomes. 18 It is worth noting that this study employed positively charged lipid DOTAP at an even higher concentration (85 mol %) than that used in EndoTAG-1 prescription.…”

Reduction-Responsive Cationic Vesicles from Bolaamphiphiles with Ionizable Amino Acid or Dipeptide Polar Heads

“…Despite the variety of cationic vesicles described, there is room for innovation considering aspects such as lowering toxicity, introducing stimuli-responsiveness, and preparing single-component vesicles from inexpensive and easily synthesized compounds. As far as toxicity is concerned, this has been an important issue both in cell cultures and in vivo experiments and constitutes a severe drawback for moving into clinical applications of cationic liposomes. − …”